Electrode array having embedded electrodes and methods of making the same

ABSTRACT

A method of manufacturing a device for brain stimulation includes forming a lead body having a distal end section and coupling at least one pre-electrode to the distal end section of the lead body. The pre-electrode defines a divider with a plurality of partitioning arms, and has a plurality of fixing lumens. A portion of the pre-electrode aligned with the portioning arms is removed to divide the pre-electrode into a plurality of segmented electrodes. Each of the plurality of segmented electrodes defines at least one of the plurality of fixing, lumens at least partially disposed through the segmented electrode. A material is introduced through the at least one fixing lumen to couple the plurality of segmented electrodes to the lead body.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.13/159,040 filed Jun. 13, 2011 which claims the benefit under 35 U.S.C.§119(e) of U.S. Provisional Patent Application Ser. No. 61/356,529 filedon Jun. 18, 2010, both of which are incorporated herein by reference.

FIELD

The invention is directed to devices and methods for brain stimulationincluding deep brain stimulation. In addition, the invention is directedto devices and method for brain stimulation using a lead having embeddedsegmented electrodes

BACKGROUND

Deep brain stimulation can be useful for treating a variety ofconditions including, for example, Parkinson's disease, dystonia,essential tremor, chronic pain, Huntington's Disease, levodopa-induceddyskinesias and rigidity, bradykinesia, epilepsy and seizures, eatingdisorders, and mood disorders. Typically, a lead with a stimulatingelectrode at or near a tip of the lead provides the stimulation totarget neurons in the brain. Magnetic resonance imaging (MRI) orcomputerized tomography (CT) scans can provide a starting point fordetermining where the stimulating electrode should be positioned toprovide the desired stimulus to the target neurons.

Upon insertion, current is introduced along the length of the lead tostimulate target neurons in the brain. This stimulation is provided byelectrodes, typically in the form of rings, disposed on the lead. Thecurrent projects from each electrode similarly and in all directions atany given length along the axis of the lead. Because of the shape of theelectrodes, radial selectivity of the current is minimal. This resultsin the unwanted stimulation of neighboring neural tissue, undesired sideeffects and an increased duration of time for the proper therapeuticeffect to be obtained.

BRIEF SUMMARY

One embodiment is a method of manufacturing a device for brainstimulation. The method includes forming a lead body having a distal endsection and coupling at least one pre-electrode to the distal endsection of the lead body. The pre-electrode defines a divider with aplurality of partitioning arms, and has a plurality of fixing lumens. Aportion of the pre-electrode aligned with the portioning arms is removedto divide the pre-electrode into a plurality of segmented electrodes.Each of the plurality of segmented electrodes defines at least one ofthe plurality of fixing lumens at least partially disposed through thesegmented electrode. A material is introduced through the at least onefixing lumen to couple the plurality of segmented electrodes to the leadbody.

Another embodiment is a device for brain stimulation that includes aninsulative tubing having a distal end section and at least one electrodeframe disposed on the distal end section of the insulative tubing. Theat least one electrode frame is formed of an insulative material. Eachof the at least one electrode frame defines at least one electrodecavity. The device also includes a plurality of segmented electrodeswith at least one of the plurality of segmented electrodes disposedwithin each of the at least one electrode cavity.

Yet another embodiment is a method of manufacturing a device for brainstimulation. The method includes forming an insulative carrier having aplurality of apertures for receiving a plurality of segmented electrodesand coupling a plurality of segmented electrodes to the insulativecarrier. One of the plurality of segmented electrodes is disposed withineach of the plurality of apertures and each of the plurality ofsegmented electrodes has at least one flange for securing the segmentedelectrode within the insulative carrier. The method also includeswrapping the insulative carrier around a mandrel to form a cylindricallead body.

A further embodiment is a method of manufacturing a device for brainstimulation. The method includes forming an insulative tubing having adistal end section and forming at least one conductor lumen through theinsulative tubing. The at least one conductor lumen extendslongitudinally through the insulative tubing. The method furtherincludes introducing a plurality of electrode tubes through the at leastone conductor lumen of the insulative tubing, and removing a portion ofthe outer surface of the insulative tubing to expose a portion of a oneof the at least one electrode tube

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting and non-exhaustive embodiments of the present invention aredescribed with reference to the following drawings. In the drawings,like reference numerals refer to like parts throughout the variousfigures unless otherwise specified.

For a better understanding of the present invention, reference will bemade to the following Detailed Description, which is to be read inassociation with the accompanying drawings, wherein:

FIG. 1A is a schematic perspective view of one embodiment of a portionof a lead having a plurality of segmented electrodes and a ringelectrode, according to the invention;

FIG. 1B is a schematic perspective view of another embodiment of a leadhaving a plurality of segmented electrodes arranged in staggeredorientation and a ring electrode, according to the invention;

FIG. 2 is a schematic diagram of radial current steering along variouselectrode levels along the length of a lead, according to the invention;

FIG. 3A is a schematic perspective view of one embodiment of apre-electrode, according to the invention;

FIG. 3B is a schematic perspective view of a second embodiment of apre-electrode, according to the invention;

FIG. 4 is a schematic perspective view of one embodiment of a segmentedelectrode, according to the invention;

FIG. 5A is a schematic perspective view of one embodiment of apre-electrode disk coupled to conductors, according to the invention;

FIG. 5B is a schematic perspective view of the pre-electrode disk ofFIG. 5A after centerless grinding, according to the invention;

FIG. 6A is a schematic perspective view of one embodiment of anelectrode frame, according to the invention;

FIG. 6B is a schematic perspective view of a second embodiment of anelectrode frame, according to the invention;

FIG. 6C is a schematic perspective view of a third embodiment of anelectrode frame, according to the invention;

FIG. 7A is a schematic perspective view of one embodiment of a segmentedelectrode corresponding to the electrode frame of FIG. 6A, according tothe invention;

FIG. 7B is a schematic perspective view of a second embodiment of asegmented electrode corresponding to the electrode frame of FIG. 6B,according to the invention;

FIG. 7C is a schematic perspective view of a third embodiment of asegmented electrode corresponding to the electrode frame of FIG. 6C,according to the invention;

FIG. 8 is a schematic perspective view of the segmented electrodes ofFIG. 7A being press fit into the electrode frame of FIG. 6A, accordingto the invention;

FIG. 9A is a schematic perspective view of one embodiment of amulti-lumen tubing, according to the invention;

FIG. 9B is a schematic perspective view of the multi-lumen tubing ofFIG. 9A after ablating portions of the tubing, according to theinvention;

FIG. 10A is a schematic perspective view of one embodiment of a leadconsisting of a multi-lumen tubing and electrode frames having aplurality of segmented electrodes, according to the invention;

FIG. 10B is a schematic perspective view of the lead of FIG. 10A afterremoving portions of the electrode frame, according to the invention;

FIG. 11A is a schematic perspective view of one embodiment of anelectrode having flanges, according to the invention;

FIG. 11B is a schematic perspective view of one embodiment of theelectrodes of FIG. 11A disposed in a carrier, according to theinvention;

FIG. 11C is a schematic side view of one embodiment of the carrier ofFIG. 11B after being wrapped to form a lead, according to the invention;

FIG. 12A is a schematic perspective view of one embodiment of a leadbody having electrode tubes, according to the invention;

FIG. 12B is a schematic perspective view of one embodiment of anelectrode tube having a groove, according to the invention; and

FIG. 13 is a schematic side view of one embodiment of a device for brainstimulation, according to the invention.

DETAILED DESCRIPTION

The present invention is directed to the area of devices and methods forbrain stimulation including deep brain stimulation. In addition, theinvention is directed to devices and method for brain stimulation usinga lead having a plurality of concentric windowed cylinders.

A lead for deep brain stimulation may include stimulation electrodes,recording electrodes, or a combination of both. A practitioner maydetermine the position of the target neurons using the recordingelectrode(s) and then position the stimulation electrode(s) accordinglywithout removal of a recording lead and insertion of a stimulation lead.In some embodiments, the same electrodes can be used for both recordingand stimulation. In some embodiments, separate leads can be used; onewith recording electrodes which identify target neurons, and a secondlead with stimulation electrodes that replaces the first after targetneuron identification. A lead may include recording electrodes spacedaround the circumference of the lead to more precisely determine theposition of the target neurons. In at least some embodiments, the leadis rotatable so that the stimulation electrodes can be aligned with thetarget neurons after the neurons have been located using the recordingelectrodes.

Deep brain stimulation devices and leads are described in the art. See,for instance, U.S. Patent Publication 2006/0149335 A1 (“Devices andMethods For Brain Stimulation”), and co-pending patent application U.S.Ser. No. 12/237,888 (“Leads With Non-Circular-Shaped Distal Ends ForBrain Stimulation Systems and Methods of Making and Using”). Each ofthese references is incorporated herein by reference in its respectiveentirety.

FIG. 13 illustrates one embodiment of a device 1300 for brainstimulation. The device includes a lead 1310, segmented electrodes 1320,a connector 1340 for connection of the electrodes to a control unit, anda stylet 1360 for assisting in insertion and positioning of the lead inthe patient's brain. The stylet 1360 can be made of a rigid material.Examples of suitable materials include tungsten, stainless steel, orplastic. The stylet 1360 may have a handle 1370 to assist insertion intothe lead, as well as rotation of the stylet and lead. The connector 1340fits over the proximal end of the lead 1310, preferably after removal ofthe stylet 1360.

In one example of operation, access to the desired position in the braincan be accomplished by drilling a hole in the patient's skull or craniumwith a cranial drill (commonly referred to as a burr), and coagulatingand incising the dura mater, or brain covering. The lead 1310 can beinserted into the cranium and brain tissue with the assistance of thestylet 1360. The lead can be guided to the target location within thebrain using, for example, a stereotactic frame and a microdrive motorsystem. In some embodiments, the microdrive motor system can be fully orpartially automatic. The microdrive motor system may be configured toperform one or more the following actions (alone or in combination):insert the lead, retract the lead, or rotate the lead. In someembodiments, measurement devices coupled to the muscles or other tissuesstimulated by the target neurons or a unit responsive to the patient orclinician can be coupled to the control unit or microdrive motor system.The measurement device, user, or clinician can indicate a response bythe target muscles or other tissues to the stimulation or recordingelectrode(s) to further identify the target neurons and facilitatepositioning of the stimulation electrode(s). For example, if the targetneurons are directed to a muscle experiencing tremors, a measurementdevice can be used to observe the muscle and indicate changes in tremorfrequency or amplitude in response to stimulation of neurons.Alternatively, the patient or clinician may observe the muscle andprovide feedback.

It will be understood that the lead 1310 for deep brain stimulation caninclude stimulation electrodes, recording electrodes, or both. In atleast some embodiments, the lead is rotatable so that the stimulationelectrodes can be aligned with the target neurons after the neurons havebeen located using the recording electrodes.

Stimulation electrodes may be disposed on the circumference of the leadto stimulate the target neurons. Stimulation electrodes may bering-shaped so that current projects from each electrode equally inevery direction at any given length along the axis of the lead. Toachieve current steering, segmented electrodes can be utilizedadditionally or alternatively. Though the following descriptiondiscusses stimulation electrodes, it will be understood that allconfigurations of the stimulation electrodes discussed may be utilizedin arranging recording electrodes as well.

In the field of deep brain stimulation, radially segmented electrodearrays (RSEA) have been developed to provide superior radial selectivityof current. Radially segmented electrode arrays are useful for deepbrain stimulation because the target structures in the deep brain areoften not symmetric about the axis of the distal electrode array. Insome cases, a target may be located on one side of a plane runningthrough the axis of the lead. In other cases, a target may be located ata plane that is offset at some angle from the axis of the lead. Thus,radially segmented electrode arrays may be useful for selectivelysimulating tissue.

FIG. 1A illustrates one embodiment of a lead 100 for brain stimulation.The device includes a lead body 110, one or more ring electrodes 120,and a plurality of segmented electrodes 130. The lead body 110 can beformed of a biocompatible, non-conducting material such as, for example,a polymeric material. Suitable polymeric materials include, but are notlimited to, silicone, polyurethanes, polyether polyurethane,polycarbonate polyurethane, or silicone-polyurethane copolymer. In atleast some instances, the lead may be in contact with body tissue forextended periods of time. In at least some embodiments, the lead has across-sectional diameter of no more than 1.5 mm and may be in the rangeof 0.75 to 1.5 mm. In at least some embodiments, the lead has a lengthof at least 10 cm and the length of the lead may be in the range of 25to 70 cm.

Stimulation electrodes may be disposed on the lead body 110. Thesestimulation electrodes may be made using a metal, alloy, conductiveoxide, or any other suitable conductive material. Examples of suitablematerials include, but are not limited to, platinum, iridium, platinumiridium alloy, stainless steel, titanium, or tungsten. Preferably, thestimulation electrodes are made of a material that is biocompatible anddoes not substantially corrode under expected operating conditions inthe operating environment for the expected duration of use.

In at least some embodiments, any of the electrodes can be used as ananode or cathode and carry anodic or cathodic current. In someinstances, an electrode might be an anode for a period of time and acathode for a period of time. In other embodiments, the identity of aparticular electrode or electrodes as an anode or cathode might befixed.

The lead contains a plurality of segmented electrodes 130. Any number ofsegmented electrodes 130 may be disposed on the lead body 110. In someembodiments, the segmented electrodes 130 are grouped in sets ofsegmented electrodes, each set disposed around the circumference of thelead at or near a particular longitudinal position. The lead may haveany number of sets of segmented electrodes. In at least someembodiments, the lead has one, two, three, four, five, six, seven, oreight sets of segmented electrodes. In at least some embodiments, eachset of segmented electrodes contains the same number of segmentedelectrodes 130. In some embodiments, each set of segmented electrodescontains three segmented electrodes 130. In at least some otherembodiments, each set of segmented electrodes contains two, four, five,six, seven or eight segmented electrodes. The segmented electrodes 130may vary in size and shape. For example, in FIG. 1B, the segmentedelectrodes 130 are shown as portions of a ring or curved rectangularportions. In some other embodiments, the segmented electrodes 130 arecurved square portions. The shape of the segmented electrodes 130 mayalso be substantially triangular, diamond-shaped, oval, circular orspherical. In some embodiments, the segmented electrodes 130 are all ofthe same size, shape, diameter, width or area or any combinationthereof. In some embodiments, the segmented electrodes of each set (oreven all segmented electrodes) may be identical in size and shape.

In at least some embodiments, each set of segmented electrodes 130 maybe disposed around the circumference of the lead body 110 to form asubstantially or approximately cylindrical shape around the lead body110. The spacing of the segmented electrodes 130 around thecircumference of the lead body 110 may vary. In at least someembodiments, equal spaces, gaps or cutouts are disposed between eachsegmented electrodes 130 around the circumference of the lead body 110.In other embodiments, the spaces, gaps or cutouts between segmentedelectrodes may differ in size or shape. In other embodiments, thespaces, gaps, or cutouts between segmented electrodes may be uniform fora particular set of segmented electrodes or for all sets of segmentedelectrodes. The segmented electrodes 130 may be positioned in irregularor regular intervals around the lead body 110.

Stimulation electrodes in the form of ring electrodes 120 may bedisposed on any part of the lead body 110, usually near a distal end ofthe lead. FIG. 1A illustrates a portion of a lead having one ringelectrode. Any number of ring electrodes may be disposed along thelength of the lead body 110. For example, the lead body may have onering electrode, two ring electrodes, three ring electrodes or four ringelectrodes. In some embodiments, the lead will have five, six, seven oreight ring electrodes. Other embodiments do not include ring electrodes.

In some embodiments, the ring electrodes 120 are substantiallycylindrical and wrap around the entire circumference of the lead body110. In some embodiments, the outer diameter of the ring electrodes 120is substantially equal to the outer diameter of the lead body 110.Furthermore, the width of ring electrodes 120 may vary according to thedesired treatment and the location of the target neurons. In someembodiments the width of the ring electrode 120 is less than or equal tothe diameter of the ring electrode 120. In other embodiments, the widthof the ring electrode 120 is greater than the diameter of the ringelectrode 120.

Conductors (not shown) that attach to or from the ring electrodes 120and segmented electrodes 130 also pass through the lead body 110. Theseconductors may pass through the material of the lead or through a lumendefined by the lead. The conductors are presented at a connector forcoupling of the electrodes to a control unit (not shown). In oneembodiment, the stimulation electrodes correspond to wire conductorsthat extend out of the lead body 110 and are then trimmed or ground downflush with the lead surface. The conductors may be coupled to a controlunit to provide stimulation signals, often in the form of pulses, to thestimulation electrodes.

FIG. 1B is a schematic perspective view of another embodiment of a leadhaving a plurality of segmented electrodes. As seen in FIG. 1B, theplurality of segmented electrodes 130 may be arranged in differentorientations relative to each other. In contrast to FIG. 1A, where thethree sets of segmented electrodes are aligned along the length of thelead body 110, FIG. 1B displays another embodiment in which the threesets of segmented electrodes 130 are staggered. In at least someembodiments, the sets of segmented electrodes are staggered such that nosegmented electrodes are aligned along the length of the lead body 110.In some embodiments, the segmented electrodes may be staggered so thatat least one of the segmented electrodes is aligned with anothersegmented electrode of a different set, and the other segmentedelectrodes are not aligned.

Any number of segmented electrodes 130 may be disposed on the lead body110 in any number of sets. FIGS. 1A and 1B illustrate embodimentsincluding three sets of segmented electrodes. These three sets ofsegmented electrodes 130 may be disposed in different configurations.For example, three sets of segmented electrodes 130 may be disposed onthe distal end of the lead body 110, distal to a ring electrode 120.Alternatively, three sets of segmented electrodes 130 may be disposedproximal to a ring electrode 120. By varying the location of thesegmented electrodes 130, different coverage of the target neurons maybe selected. For example, a specific configuration may be useful if thephysician anticipates that the neural target will be closer to thedistal tip of the lead body 110, while another arrangement may be usefulif the physician anticipates that the neural target will be closer tothe proximal end of the lead body 110. In at least some embodiments, thering electrodes 120 alternate with sets of segmented electrodes 130.

Any combination of ring electrodes 120 and segmented electrodes 130 maybe disposed on the lead. In some embodiments the segmented electrodesare arranged in sets. For example, a lead may include a first ringelectrode 120, two sets of segmented electrodes, each set formed ofthree segmented electrodes 130, and a final ring electrode 120 at theend of the lead. This configuration may simply be referred to as a1-3-3-1 configuration. It may be useful to refer to the electrodes withthis shorthand notation. Other eight electrode configurations include,for example, a 2-2-2-2 configuration, where four sets of segmentedelectrodes are disposed on the lead, and a 4-4 configuration, where twosets of segmented electrodes, each having four segmented electrodes 130are disposed on the lead. In some embodiments, the lead will have 16electrodes. Possible configurations for a 16-electrode lead include, butare not limited to 4-4-4-4, 8-8, 3-3-3-3-3-1 (and all rearrangements ofthis configuration), and 2-2-2-2-2-2-2-2.

FIG. 2 is a schematic diagram to illustrate radial current steeringalong various electrode levels along the length of a lead. Whileconventional lead configurations with ring electrodes are only able tosteer current along the length of the lead (the z-axis), the segmentedelectrode configuration is capable of steering current in the x-axis,y-axis as well as the z-axis. Thus, the centroid of stimulation may besteered in any direction in the three-dimensional space surrounding thelead body 110. In some embodiments, the radial distance, r, and theangle θ around the circumference of the lead body 110 may be dictated bythe percentage of anodic current (recognizing that stimulationpredominantly occurs near the cathode, although strong anodes may causestimulation as well) introduced to each electrode as will be describedin greater detail below. In at least some embodiments, the configurationof anodes and cathodes along the segmented electrodes 130 allows thecentroid of stimulation to be shifted to a variety of differentlocations along the lead body 110.

As can be appreciated from FIG. 2, the centroid of stimulation can beshifted at each level along the length of the lead. The use of multiplesets of segmented electrodes 130 at different levels along the length ofthe lead allows for three-dimensional current steering. In someembodiments, the sets of segmented electrodes 130 are shiftedcollectively (i.e. the centroid of simulation is similar at each levelalong the length of the lead). In at least some other embodiments, eachset of segmented electrodes 130 is controlled independently. Each set ofsegmented electrodes may contain two, three, four, five, six, seven,eight or more segmented electrodes. It will be understood that differentstimulation profiles may be produced by varying the number of segmentedelectrodes at each level. For example, when each set of segmentedelectrodes includes only two segmented electrodes, uniformly distributedgaps (inability to stimulate selectively) may be formed in thestimulation profile. In some embodiments, at least three segmentedelectrodes 130 are utilized to allow for true 360° selectivity.

In addition to 360° selectivity, a lead having segmented electrodes mayprovide several advantages. First, the lead may provide for moredirected stimulation, as well as less “wasted” stimulation (i.e.stimulation of regions other than the target region). By directingstimulation toward the target tissue, side effects may be reduced.Furthermore, because stimulation is directed toward the target site, thebattery in an implantable pulse generator may last for a longer periodof time between recharging.

As previously indicated, the foregoing configurations may also be usedwhile utilizing recording electrodes. In some embodiments, measurementdevices coupled to the muscles or other tissues stimulated by the targetneurons or a unit responsive to the patient or clinician can be coupledto the control unit or microdrive motor system. The measurement device,user, or clinician can indicate a response by the target muscles orother tissues to the stimulation or recording electrodes to furtheridentify the target neurons and facilitate positioning of thestimulation electrodes. For example, if the target neurons are directedto a muscle experiencing tremors, a measurement device can be used toobserve the muscle and indicate changes in tremor frequency or amplitudein response to stimulation of neurons. Alternatively, the patient orclinician may observe the muscle and provide feedback.

Radially segmented electrode arrays may be manufactured in a variety ofways, for example, by embedding or coupling conductive portions in alead body. In at least some embodiments, a disk having an inner cavitymay be used to form a radially segmented electrode array. The disk maydefine various lumens for housing conductors and for facilitatingattachment to the lead body. Radially segmented electrode arrays mayalso be formed by disposing electrodes in an electrode frame or in alumen defined by the lead body.

In some embodiments a pre-electrode is used to form a radially segmentedelectrode array. FIG. 3A is a schematic perspective view of oneembodiment of a pre-electrode disk 300. The pre-electrode may be formedof a conductor such as a metal, alloy, conductive oxide, or any othersuitable conductive material. In some embodiments, the pre-electrode 300is formed of platinum, platinum-iridium, iridium, 316L stainless steel,tantalum, nitinol or a conductive polymer. The shape and size of thepre-electrode 300 may be modified. As seen in FIG. 3A, the pre-electrode300 may be formed in the shape of a disk. In some embodiments, thepre-electrode 300 is formed of a substantially cylindrical member havinga diameter larger than the desired final diameter of the lead. It willbe understood that the pre-electrode 300 need not be substantiallycylindrical, but may also be formed in the shape of a cube (see e.g.,FIG. 3B), or any other polyhedron. In such embodiments, a cylindricallead may be obtained by grinding (e centerless grinding), machining, orablating the outer diameter of the pre-electrode 300.

The pre-electrode 300 defines a divider 310. The divider 310 may beformed of any shaped passage that extends through the longitudinal axisof the pre-electrode 300. As seen in FIG. 3A, in some embodiments, thedivider 310 is formed of a central passage having three partitioningarms. The three partitioning arms will divide the pre-electrode 300 intothree segmented electrodes as will be described with reference to FIGS.4, 5A and 5B. It will be understood that the size and shape of thedivider 310 may be varied and that the divider 310 may be formed in anypattern suitable for dividing the pre-electrode 300 into a desirednumber of partitions. In some embodiments, the divider also includes acentral lumen for passage of a stylet.

The pre-electrode 300 may include one or more conductor lumens 320. Theconductor lumen 320 may be any lumen, hole, or passage that extendsthrough the longitudinal axis of the pre-electrode 300. In someembodiments, the pre-electrode 300 includes one, two, three, four, five,six, eight, ten, or twelve conductor lumens 320. In some embodiments,the pre-electrode 300 includes one conductor lumen 320 for eachsegmented electrode that will be formed from the pre-electrode 300. Forexample, if a divider 310 is configured such that three segmentedelectrodes will be formed from the pre-electrode 300, then threeconductor lumens 320 may be formed, one for each segmented electrode.The size of the conductor lumens 320 may be varied as needed. In someembodiments, the conductor lumens 320 are defined to have a circularcross-section corresponding to the cross-section of conductors that willbe coupled to the electrodes. In some embodiments, the cross-section ofthe conductor lumens 320 are the same size and shape. Alternatively, theconductor lumens 320 may be formed in different shapes or sizes. Forexample, the conductor lumen 320 may have a cross-section that is in theshape of a square, a rectangle, an oval, or a triangle.

In some embodiments, the pre-electrode 300 includes one or more fixinglumens 330. The fixing lumen 330 may be any lumen, hole, or passage thatextends through the longitudinal axis of the pre-electrode 300. In someembodiments, the fixing lumen 330 only partially extends through thelongitudinal axis of the electrode 300. In at least some otherembodiments, the fixing lumen 330 is defined as a through hole, apassage that extends through the full length of the pre-electrode 300.The fixing lumen 330 may be similar to the conductor lumen 320 in shapeand size. The fixing lumen 330 may also be of different shape or sizethan the conductor lumen 320. In some embodiments, the fixing lumen 330has a circular cross-section. As seen in FIG. 3A, the fixing lumen 330may have a smaller cross-section than the conductor lumen 320.

FIG. 3B is a schematic perspective view of a second embodiment of apre-electrode 300. The pre-electrode 300 of FIG. 3B includes fixinglumens 330 and conductor lumens 320. The pre-electrode 300 also includesa divider 310 with four partitioning arms. As previously noted, adivider 310 may include any number of partitioning arms such as three,four, five, six, eight, ten, or twelve portioning arms. Thus, a singlepre-electrode 300 may be used to form four segmented electrodes. As canbe seen in FIG. 3B, the pre-electrode 300 is formed in the shape of acube. The cube-shaped pre-electrode 300 may be further processed to formsegmented electrodes having the desired shape and size.

FIG. 4 is a schematic perspective view of one embodiment of a segmentedelectrode 400. The segmented electrode 400 may be the result ofpartitioning the pre-electrode 300 of FIG. 3A along divider 310. In someembodiments, after partitioning the pre-electrode 300, each segmentedelectrode 400 includes a single fixing lumen 330 and a single conductorlumen 320. It will be understood that the pre-electrodes 300 andsegmented electrodes 400 may be configured such that each segmentedelectrode 400 includes any number of fixing lumens 330 or conductorlumens 320.

FIG. 5A is a schematic perspective view of one embodiment of apre-electrode 300 before grinding. Although the pre-electrode 300 ofFIG. 5A is disk-shaped, the pre-electrode 300 may be formed of anysuitable shape. The pre-electrode 300 includes a plurality of fixinglumens 330. The fixing lumens 330 allow for coupling or locking portionsof the pre-electrode 300 to the lead body 110 (not shown) by reflowing aportion of the lead body 110 to allow it to pass through the fixinglumens 330. In some embodiments, additional fixing material similar tothe lead body 110 is disposed within the fixing lumen 330. The fixingmaterial may be composed of the same material or any other materialcapable of reflowing with the lead body 110. In some embodiments,portions of the pre-electrode 300 are further bonded to the lead body110 with a potting agent or adhesive such as epoxy.

FIG. 5A further illustrates conductors 510 being disposed through theconductor lumens 320. In some embodiments, the conductors 510 have adiameter corresponding to the diameter of the conductor lumens 320. Asseen in FIG. 5A, a conductor 510 may be coated or wrapped with aninsulator 520. The conductors 510 may also include ablated portions 530.The ablated portions 530 allow for electrical coupling between theconductor 510 and the segmented electrode. In some embodiments, theportions of the conductors 510 are disposed within the conductor lumens320 of the pre-electrode 300 then welded to a portion of thepre-electrode 300. It will be understood than any other method suitablefor electrically coupling a pre-electrode 300 to a conductor 510 may beused.

The pre-electrodes 300 may be formed larger in diameter than the leadbody 110. Furthermore, the pre-electrodes 300 is yet undivided. In someembodiments, it may be useful or desirable to grind down thepre-electrode 300 to an appropriate diameter. After the pre-electrodes300 have been ground down to the same level as the lead body 110, thelead 100 is isodiametric, having substantially the same diameter in alldirections. The result is a substantially cylindrical lead 100 that issuitable for deep brain stimulation. Grinding down the pre-electrodes300 is also capable of forming segmented electrodes 400 from thepre-electrodes 300. Preferably, the pre-electrodes are ground after thepre-electrodes are fixed within the lead and coupled to the conductors.

FIG. 5B is a schematic perspective view of the pre-electrode 300 of FIG.5A after grinding. In some embodiments, grinding the pre-electrode 300results in grinding portions of the pre-electrode down to the divider310, thus forming separate segmented electrodes 400. As can beappreciated from FIG. 5B, three segmented electrodes 400 are formed atone level of the lead body 110. A plurality of pre-electrodes 300 may bedisposed at predetermined longitudinal levels of the lead body 100 tocreate leads having variable stimulation profiles. In some embodiments,the segmented electrodes 400 are electrically insulated from one anotherso that the stimulation directed to each segmented electrode 400 isindependently-controlled.

In some other embodiments a pre-formed electrode frame may be used toform a lead having a plurality of segmented electrodes. FIG. 6Aillustrates an electrode frame 610 capable of housing a plurality ofsegmented electrodes. The electrode frame 610 may be formed of abiocompatible, non-conducting material such as, for example, a polymericmaterial. Suitable polymeric materials include, but are not limited to,polyetheretherketone (PEEK), polytetrafluoroethylene (e.g., Teflon™),polyimide, silicone, polyurethanes, polyether polyurethane,polycarbonate polyurethane, and silicone-polyurethane copolymer.

The electrode frame 610 defines a plurality of electrode chambers 620for accepting a plurality of segmented electrodes. The embodiment ofFIG. 6A illustrates an electrode frame 610 having three electrodechambers 620. It will be understood that the electrode frame 610 mayinclude any number of electrode chambers 620. In some embodiments, theelectrode frame 610 includes one, two, three, four, five, six, seven,eight, nine, ten, twelve, fourteen or sixteen electrode chambers 620.The electrode chambers 620 may also be defined to house segmentedelectrodes of the same or different shape or size. In at least someembodiments, the electrode chambers 620 are of the same shape and size.In some embodiments, the electrode chambers 620 fully enclose thesegmented electrodes. The electrode chambers 620 may be equally spacedabout the electrode frame 610. As illustrated, in some embodiments, theelectrode frame 610 is C-shaped with an opening 630 configured forcoupling the electrode frame 610 to a tubing as will be described ingreater detail with reference to FIG. 10A. The electrode frame 610 mayalso include longitudinally extending grooves 640 on the interior of theelectrode frame 610. The grooves 640 may be configured to houseconductors (not shown).

FIGS. 6B and 6C are schematic perspective views of a second and thirdembodiment of an electrode frame 610. As seen in FIGS. 6B and 6C, theelectrode frames 610 may include various electrode chambers 620 with avariety of different shapes. For example, the electrode frames 610 maybe formed to house different-shaped segmented electrodes. As seen inFIG. 6C, in some embodiments, the electrode frame 610 lacks an opening636, but is formed slightly larger in diameter so as to be press fitover the lead body.

The segmented electrodes 710 may be formed of platinum,platinum-iridium, iridium, 316L stainless steel, tantalum, nitinol, aconductive polymer, or any other suitable conductive material. FIG. 7Ais a schematic perspective view of one embodiment of a segmentedelectrode 710 corresponding to the electrode frame 610 of FIG. 6A,formed of an elongate member with an arched cross-section. FIG. 7B is aschematic perspective view of a second embodiment of a segmentedelectrode 710 corresponding to the electrode frame 610 of FIG. 6B. Thesegmented electrode 710 of FIG. 7B has a triangular cross-section. FIG.7C is a schematic perspective view of a third embodiment of a segmentedelectrode 710 corresponding to the electrode frame 610 of FIG. 6C. Aseen in FIGS. 7A-C, the segmented electrodes 710 may be formed in avariety of shapes and sizes. In some embodiments, the segmentedelectrodes 710 are formed of elongate members having a circular, ovoid,rectangular, square, hexagonal, star-shaped, cruciform, trapezoidal, ora patterned cross-section (e.g. the cross-section shown in FIG. 7C). Asseen in FIGS. 7B and 7C, in some embodiments, the segmented electrodes710 include fastening features 720 to aid in fastening them to theelectrode frame 610. For example, the fastening feature 720 may be anyof a hole, key, seam, neck, shoulder, or rib.

FIG. 8 is a schematic perspective view of the segmented electrodes 710of FIG. 7A being inserted into the electrode chambers 620 of theelectrode frame 610 of FIG. 6A. As seen in FIG. 8, the segmentedelectrode 710 may be press fit into the electrode frame 610. Othermethods may be used to further affix or couple the segmented electrode710 to the electrode frame 610. For example, a potting agent or adhesivemay be used to affix the segmented electrode 710 to the electrode frame610. In at least some embodiments, fastening features 720, whichcorrespond to the shape of the electrode chambers 620 are useful formaintaining a proper fit between an electrode frame 610 and a segmentedelectrode 710.

FIG. 9A is a schematic perspective view of one embodiment of amulti-lumen tubing 900. The multi-lumen tubing 900 may be formed of anymaterial or combination of materials used in forming a lead body. Themulti-lumen tubing 900 may define a central passage 910 configured toreceive a stylet or other insertion instrument. Though the centralpassage 910 is illustrated as a passage having a circular cross-section,any shaped central passage 910 may be formed. In some embodiments, thecentral passage 910 has a cross-section corresponding to thecross-section of a stylet. The multi-lumen tubing 900 may define aplurality of longitudinally disposed conductor lumens 930. Any number ofconductor lumens 930 may be defined within the multi-lumen tubing 900.In some embodiments, one, two, three, four, five, six, seven, eight,nine, ten, twelve or more conductor lumens 930 may be defined by themulti-lumen tubing 900. In some embodiments, the number of conductorlumens 930 corresponds to the number of electrodes that will be disposedon the tubing 900.

Portions of the multi-lumen tubing 900 may be removed to allow thecoupling of the electrode frame 610. FIG. 9B is a schematic perspectiveview of the multi-lumen tubing 900 of FIG. 9A after ablating portions ofthe tubing 900. It will be understood that any method may be used forremoving sections of multi-lumen tubing 900. For example, portions ofthe multi-lumen tubing 900 may be ground down to form slots 920.Alternatively, slots 920 may also be formed by ablating the outer layerof the multi-lumen tubing 900 using, for example, laser ablation. Theresulting slots 920 may have dimensions corresponding to the dimensionsof the electrode frame 610, so that the electrode frame 610 iscoupleable to the multi-lumen tubing 900.

The electrode frames 610 may be coupled to the multi-lumen tubing 900.FIG. 10A is a schematic perspective view of one embodiment of a leadconsisting of a multi-lumen tubing 900 and electrodes frames 610disposed on the tubing 900. In some embodiments, the electrode frame 610is flexible and configured so that the opening 630 of the electrodeframe 610 allows coupling to the multi-lumen tubing 900. In at leastsome other embodiments, the electrode frames 610 are configured to slideover the tubing 900. After coupling the electrode frames 610 and themulti-lumen tubing 900, the tubing 900 and the electrode frame 610 maybe reflowed to form a lead 1000. In some embodiments, the tubing 900 andelectrode frames 610 are configured so that during the reflow process,material is reflowed through fixing lumens. By reflowing materialthrough the fixing lumen, a more reliable lead 1000 may be formed thatis less prone to breakage and failure. Individual conductors may bedisposed through conductor lumens 930 and the grooves 640 and welded tothe individual segmented electrodes 710.

As seen in FIG. 10B, portions of the outer surface of the electrodeframe 610 may also be removed (e.g., by ablation, grinding, and thelike) to expose the segmented electrode 710. The outer surfaces of theelectrode frames 610 may be removed in any pattern as desired. Forexample, in some embodiments, the outer surface of the electrode frame610 is removed at one or more positions corresponding to each of thesegmented electrodes 710 that are housed within. In at least someembodiments, an isodiametric lead is formed by grinding the outersurface of the electrode frame 610 and the lead body to the samediameter. When the outer surface of the electrode frame 610 is removed,the outer portion of the electrode chamber 620 is removed to form anelectrode cavity and the electrodes 710 are exposed at the surface ofthe lead. In at least some embodiments, each segmented electrode 710 iselectrically coupled to an independent conductor (not shown) disposedwithin one of the lumens 930 so that each segmented electrode 710 may beindependently activated.

Liquid injected molding may also be used to create a lead array. FIG.11A is a schematic perspective view of one embodiment of a segmentedelectrode 1110. The segmented electrode 1110 may be similar to thosedescribed in other embodiments. In some embodiments, the segmentedelectrode 1110 is a rectangular portion having legs and includes flanges1120. In some embodiments, each segmented electrode 1110 includes oneflange 1120 on each side, though it will be understood that thesegmented electrode 1110 may include any number of flanges 1120.

FIG. 11B is a schematic perspective view of one embodiment of thesegmented electrode 1110 of FIG. 11A disposed in a carrier 1150. Thecarrier 1150 may be a tray-like member formed of any suitable insulativematerial capable of housing the segmented electrodes 1110. Suitablematerials for the carrier 1150 include, but are not limited to polymers(including plastics), composite materials, and the like. In someembodiments, the carrier 1150 is formed of silicone. The carrier 1150includes apertures 1160 for receiving the segmented electrodes 1110. Insome embodiments, the apertures 1160 are formed of the same or differentshapes and sizes. In some embodiments, the apertures 1160 correspond tothe size and shape of the segmented electrodes 1110. Furthermore, theapertures 1160 may be formed in any pattern along the surface of thecarrier 1150.

The carrier 1150 may also include side holes 1170 to allow for thepassage of conductors (not shown) to the segmented electrodes 1110. Insome embodiments, each aperture 1160 corresponds to one or more sideholes 1170. The side holes 1170 may be formed in any edge or face of thecarrier 1150. In some embodiments, as seen in FIG. 11B, the side holes1170 are aligned along one edge of the carrier 1150. It will beunderstood that any number of side holes 1170 may be formed in thecarrier 1150 in any pattern or alignment, such as in multiple rows.

As seen in FIG. 11B, the segmented electrodes 1110 may be press fit intothe apertures 1160 of the carrier 1150. In some embodiments, thesegmented electrodes 1110 are locked in place by the flanges 1120 on thesides. The flanges 1120 may be configured to mate with a side of theapertures 1160. With the segmented electrodes 1110 locked in place, thecarrier 1150 may be wrapped around a mandrel and reflowed to form a leadas seen in FIG. 11C.

In another embodiment, a tubing 1200 similar to that of the multi-lumentubing 900 is provided. The tubing 1200 may be provided with a pluralityof conductor lumens 1220. The tubing 1200 may also include a centralpassage 1210 configured for receiving an insertion instrument such as astylet. Pre-welded electrode tubes 1250 may be disposed within theconductor lumens 1220.

FIG. 12A is a schematic perspective view of one embodiment of a tubing1200 having electrode tubes 1250. The electrode tubes 1250 may be shortin length and inserted only in conductor lumens on sides of themulti-lumen tubing 1200 where stimulation is desired. In someembodiments, electrodes tubes 1250 are inserted only at the extremitiesof the multi-lumen tubing 1200. The electrode tubes 1250 may be pressfit within the multi-lumen tubing 1200 to avoid slippage duringmanufacture and usage. In some embodiments, additional methods may beused to enhance coupling between the electrodes tubes 1250 and themulti-lumen tubing 1200, such as, for example, the use of epoxy withinthe conductor lumens 1220.

In some embodiment, the electrode tubes 1250 have a groove 1270 that maybe useful in coupling the electrode tube 1250 to the tubing 1200. Asseen in FIG. 12B, the groove 1270 may be longitudinally positioned alongthe electrode tube 1250. Moreover, the conductor lumen 1220 may bedefined to have a cross-sectional shape that will aid in fastening theelectrode tube 1250 to the tubing 1200. It will be understood that anynumber of grooves 1270 may be positioned on the electrode tube 1250.

With the electrode tubes 1250 disposed within the multi-lumen tubing1200, techniques such as grinding or ablation may be used to exposeportions of the electrode tubes 1250 by removing portions of the outersurface of the tubing 1200. As seen in FIG. 12A, the locations ofablation 1260 may be chosen in any pattern as desired.

Modifications of these methods are possible. For example, one or morecombinations of the above methods may be used to form a lead as desired.In some embodiments, these methods are used with lead constructionsother than deep brain stimulation leads.

The above specification, examples and data provide a description of themanufacture and use of the composition of the invention. Since manyembodiments of the invention can be made without departing from thespirit and scope of the invention, the invention also resides in theclaims hereinafter appended.

What is claimed as new and desired to be protected by Letters Patent ofthe United States is:
 1. A method of manufacturing a device for brainstimulation, the method comprising: forming a lead body having a distalend section; coupling at least one pre-electrode to the distal endsection of the lead body, the pre-electrode defining a divider with aplurality of partitioning arms and having a plurality of fixing lumens;removing a portion of the pre-electrode aligned with the partitioningarms to divide the pre-electrode into a plurality of segmentedelectrodes, each of the plurality of segmented electrodes defining atleast one of the plurality of fixing lumens at least partially disposedthrough the segmented electrode; and introducing a material through theat least one fixing lumen to couple the plurality of segmentedelectrodes to the lead body.
 2. The method of claim 1, wherein the atleast one fixing lumen is a through hole.
 3. The method of claim 1,wherein each of the plurality of segmented electrodes further defines atleast one conductor lumen.
 4. The method of claim 3, further comprisingdisposing at least one conductor within each of the at least oneconductor lumen.
 5. The method of claim 1, wherein introducing amaterial comprises reflowing a portion of the lead body through the atleast one fixing lumen.
 6. The method of claim 1, wherein the dividerhas exactly three partitioning arms.
 7. The method of claim 1, whereinthe divider further defines a central lumen.
 8. The method of claim 1,wherein removing the portion of the pre-electrode comprises grinding thepre-electrode to remove the portion of the pre-electrode and divide thepre-electrode into the plurality of segmented electrodes.
 9. The methodof claim 8, wherein grinding the pre-electrode comprises grinding thepre-electrode so that the plurality of segmented electrodes and leadbody are isodiametric.
 10. The method of claim 1, wherein removing theportion of the pre-electrode occurs after introducing the materialthrough the at least one fixing lumen.
 11. The method of claim 1,wherein the at least one fixing lumen extends only partially through thepre-electrode.
 12. The method of claim 1, wherein the at least onefixing lumen is a plurality of fixing lumens with at least one of thefixing lumens defined within each of the segmented electrodes.
 13. Themethod of claim 1, further comprising coupling at least one conductor toeach of the plurality of segmented electrodes.
 14. A method ofmanufacturing a device for brain stimulation, the method comprising:forming an insulative carrier having a plurality of apertures forreceiving a plurality of segmented electrodes; coupling a plurality ofsegmented electrodes to the insulative carrier, wherein a one of theplurality of segmented electrodes is disposed within each of theplurality of apertures, each of the plurality of segmented electrodeshaving at least one flange for securing the segmented electrode withinthe insulative carrier; and wrapping the insulative carrier around amandrel to form a cylindrical lead body.
 15. The method of claim 14,wherein each of the at least one flange is configured to mate with aside of at least one of the apertures.
 16. The method of claim 14,further comprising forming at least one hole on a face of the insulativecarrier, the at least one hole being configured and arranged to receivea conductor.
 17. The method of claim 14, wherein coupling, a pluralityof segmented electrodes comprises press fitting the plurality ofsegmented electrodes into the plurality of apertures of the insulativecarrier.
 18. A method of manufacturing a device for brain stimulation,the method comprising: forming an insulative tubing having a distal endsection; forming at least one conductor lumen through the insulativetubing, the at least one conductor lumen extending longitudinallythrough the insulative tubing; introducing a plurality of electrodetubes through the at least one conductor lumen of the insulative tubing,and removing a portion of the outer surface of the insulative tubing toexpose a portion of a one of the at least one electrode tube.
 19. Themethod of claim 18, wherein each of the at least one electrode tubedefines a groove configured to secure the electrode tube to theinsulative tubing.
 20. The method of claim 18, wherein forming at leastone conductor lumen comprises forming a plurality of conductor lumensequally spaced about the circumference of the insulative tubing.